1. Field of the Invention
The present invention relates to dispensing containers for rolls of light-sensitive material.
2. Description of the Prior Art
Containers for dispensing unexposed photographic film or paper from a roll are well known in the art and generally are fabricated of heavy paper, paper board, fiberboard or corrugated paperboard, such as shown in U.S. Pat. No. 3,481,457, which issued Dec. 2, 1969 to D. D. Overton III et al. Some such containers are more economically made of thin, opaque plastic which may be thermoformed into shaped blanks of various desired configurations. After shaping, the blank is folded into a tubular configuration, such as shown in our commonly-assigned U.S. Pat. No. 4,239,164, which issued Dec. 16, 1980.
While thin plastic containers have many manufacturing economies and user advantages, the opaque material of which they are formed has an undesirable characteristic of thinning out when a corner is folded with a small curvature radius. This thinning out, commonly referred to as "blushing," may result in loss of opaqueness and light integrity at the corners. To prevent blushing, the container shown in the above U.S. patent utilizes curved corners of large radii and separate end caps supplied after the main container body has been formed. While this offers a good light-tight container for many uses, there are certain advantages to having a container with sharper edges and integral end caps. To this end, the present invention provides light protection for the contents of such containers even though blushing can occur. Besides the light protection feature, the invention also provides double material thicknesses at the corners for structural strength.